Current CV markers, LDL-C, HDL-C, and total cholesterol, are not able to identify coronary artery disease (CAD) patients or subjects that have an elevated risk for CV complications, such as AMI, ACS, stroke and CV death, from patients having more stable disease.
The term myocardial infarction pathologically denotes the death of cardiac myocytes due to extended ischemia, which may be caused by an increase in perfusion demand or a decrease in blood flow. The event is called “acute” if it is sudden and serious. Diagnosis of AMI is determined by a high clinical suspicion from history and physical examination, in addition to changes in cardiac biomarkers (creatinine kinase MB [CK-MB], troponins, and myoglobin) and electrocardiogram (ECG) findings. Imaging techniques, such as two-dimensional echocardiography, are also useful in demonstrating myocardial dysfunction. Current CV markers, LDL-C, HDL-C, and total cholesterol, however, only identify when the damage of heart tissue has already occurred. They fail to predict the likelihood of the CVD complication occurring.
Acute coronary syndrome (ACS) is a term used for any condition brought on by sudden, reduced blood flow to the heart. The first sign of acute coronary syndrome can be sudden stopping of the heart called cardiac arrest. Acute coronary syndrome is often diagnosed in an emergency room or hospital with same cardiac biomarkers or electrocardiogram (ECG) as AMI, that provide evidence on damaged heart tissue or problems in heart's electric activity.
A stroke is the loss of brain function due to a disturbance in the blood supply to the brain, depriving brain tissue of oxygen and food. Within minutes, brain cells begin to die. A stroke may be caused by a blocked artery (ischemic stroke) or a leaking or burst blood vessel (hemorrhagic stroke). Some people may experience a temporary disruption of blood flow through their brain (transient ischemic attack, or TIA). Strokes are usually diagnosed by brain imaging and carrying out physical tests.
Sudden cardiac death (SCD) is a sudden, unexpected death caused by loss of heart function, also named as sudden cardiac arrest (SCA). Sudden cardiac arrest is not a heart attack (myocardial infarction). Heart attacks occur when there is a blockage in one or more of the coronary arteries, preventing the heart from receiving enough oxygen-rich blood. In contrast, sudden cardiac arrest occurs when the electrical system to the heart malfunctions and suddenly becomes very irregular. The heart beats dangerously fast. Ventricular fibrillation may occur, and blood is not delivered to the body. In the first few minutes, the greatest concern is that blood flow to the brain will be reduced so drastically that a person will lose consciousness. Death follows unless emergency treatment is begun immediately. Sudden cardiac arrest happens without warning and is rarely diagnosed with medical tests as its happening. Instead, SCA often is diagnosed after it happens, by ruling out other causes of a person's sudden collapse.
AMI, ACS, stroke and sudden cardiac death are diagnosed in acute stage, but predictive markers are not available. The risk factors behind these events are for example, age, hypolipidemia, hypertension, smoking, diabetes, CAD or previous heart attack. Yet, no diagnostic test that could predict the events exists, and cardiovascular diseases are the leading cause of death worldwide. Furthermore, CVD costs for society more than any other group of diseases. The same tests that are used for diagnosing CVD are utilized in predicting the events. Today the most innovative approach is to use LDL-C, HDL-C, Lp(a), Lp-PLA2 (PLAC test) or CRP. However, none of the listed lipid based markers (LDL-C, HDL-C, Lp(a), Lp-PLA2 (PLAC test)) provide clinically useful predictive information allowing stratification aid to physicians. CRP has been promising in the research setting, however it has proven to be unspecific (CRP is an acute phase reactant that can react to many different stimuli leading to highly variable test results) and thus CRP values are difficult to interpret in the clinical use. There is an unmet need for a diagnostic test that could predict CV complications, such as AMI (acute myocardial infarction), ACS (acute coronary syndrome), stroke and CV death.
The ceramide based risk stratification offers superior p-values compared to any other lipid based biomarker today. Furthermore, the levels of plasma ceramides can be affected with specific lipid lowering treatments (such as statins) and, therefore, ceramide markers offer precise and actionable risk stratification.
A large group of lipid molecules, including certain ceramides, and ratios calculated from two lipid molecules have been identified for predicting CV outcomes in CAD patients who are undergoing statin treatment or who are not undergoing statin treatment (Zora Biosciences patent applications WO2013068373 and WO2013068374) or for identifying high-risk CAD patients or predicting whether a subject is at risk for developing CV complications (Zora Biosciences patent application U.S. Ser. No. 13/695,766 and U.S. Ser. No. 13/805,319).
However, there remains a need for improved methods of predicting the risk of a patient developing a CV complication, such as AMI, ACS, stroke, and CV death.